Standard and Guidelines: Intracranial Dural Arteriovenous Shunts

Abstract

Intracranial dural arteriovenous shunts (DAVS), also known as dural arteriovenous fistulas or dural arteriovenous malformations, are abnormal connections between dural (and occasionally pial) arteries and the veno vasora within the dura mater, comprising the walls of the dural sinuses, the leptomeningeal (bridging) veins, or the transosseous emissary veins within or adjacent to the dura mater. DAVS are rare, accounting for about 5–15% of intracranial vascular malformations.1 ,2 Although incompletely understood, DAVS are thought to be acquired lesions3 resulting from dural sinus or cortical venous thrombosis, possibly precipitated by hormonal changes, hypercoagulability states, trauma, or a combination of these factors.4–6 The clinical implications of intracranial DAVS are directly associated with its venous drainage pattern. For example, intracranial DAVS can cause either intracranial hemorrhages or non-hemorrhagic neurologic events such as regional or global venous congestive encephalopathy. The aims of this document are (1) to review existing knowledge about the natural history, diagnostic methodology, and treatment modalities/techniques for DAVS; and (2) to provide recommendations on management strategies for intracranial DAVS using evidence-based medicine approaches when possible but, of necessity, relying frequently on expert opinion concerning this rare disease. Recommendations follow the American College of Cardiology/American Heart Association (ACC/AHA) Classification of Recommendation/Level of Evidence (COR/LOE) and the definition of classes and levels of evidence used in the AHA/American Stroke Association (AHA/ASA) recommendations (tables 1 and 2). View this table: Table 1 ACC/AHA Classification of Recommendations and Level of Evidence (COR/LOE) View this table: Table 2 Definition of classes and levels of evidence used in AHA/ASA recommendations Given the rarity of DAVS and the challenge of diagnosing them with non-invasive tools, the natural history of intracranial DAVS is not completely understood. There are few data on the progressive enlarge of DAVS over time with respect to recruitment or enlargement of arterial feeders or appearance of de novo fistulas over time. …